Electrical properties of epitaxially grown VOx thin films

High quality VOx thin films on MgO(1 0 0) substrates were prepared and studied from the structural and electronic point of view. Epitaxial growth was confirmed by RHEED and XRD techniques. The oxygen content of VOx thin films as a function of oxygen flux was determined using RBS. The upper and lower stoichiometry limit found are similar to the ones known for bulk material (0.8–1.3). Conductivity measurements have been performed to characterize the electronic structure of our films. Thin VOx films showed mostly a semiconducting behavior. The resistivity was highly temperature and composition dependent and considerably larger than the resistivity of bulk material having the same composition. At low temperatures variable-range hopping conduction was observed, giving evidence for the presence of weak localization in VOx.